Well pressure sealing cup reinforcing structure and method of manufacture

ABSTRACT

An improved reinforcing structure and method of making said structure are disclosed. The improved reinforcing structure is a polyfurcated cylinder having an integral base portion and a tines portion. The method of manufacture includes the steps of rolling a polyfurcated plate with an integral base and tines portion, rolling the base portion into a cylindrical shape and securing the abutting ends of the base.

United States Patent [19] Berry et al.

[ WELL PRESSURE SEALING CUP REINFORCING STRUCTURE AND METHOD OFMANUFACTURE [76] Inventors: Robert F. Berry, l0318 Church Rd.,

ljallas Tex. 75 238 Henry W.

Blackwell, Rt. 1, Venus, Tex. 76084 [22] Filed: Jan. 8, 1973 [21] Appl.No.: 321,621

Related US. Application Data [62] Division of Ser. No. 166,171, July 26,1971, Pat. No.

[52] US. Cl. 277/212 C, 29/1935 [51] Int. Cl F16j 9/08 [58] Field ofSearch 277/212 R, 212 C, 212 F, 277/181; 16/2; 92/241; 29/1935 [56]References Cited UNITED STATES PATENTS 665,873 1/1901 Budd 29/190 [45.]June 25, 1974 1,825,185 9/1931 Greenidge 277/212 C 2,619,393 11/1952Wilson et al.... 2,799,237 7/1957 Martines 29/1935 X PrimaryExaminer-Samuel B. Rothberg Attorney, Agent, or Firm-William E. Johnson,Jr.; Michael J. Caddell; Morgan L. Crow 57] ABSTRACT Cl 9 W SF WS,

WELL PRESSURE SEALING CUP REINFORCING STRUCTURE AND METHOD OFMANUFACTURE CROSSREFERENCE TO RELATED APPLICATION This application is adivisional application of an original copending application, Ser. No.166,171 filed July 26, 1971, by Robert F. Berry and Henry W. Blackwell;now U.S. Pat. No. 3,722,053 issued Mar. 27, 1973.

BACKGROUND OF THE INVENTION The field of invention relates to welloperations in which a swabbing operation may be performed. Swabbinggenerally is the removal of liquid from a well by means of a sealingelement mounted on a tool and lowered into a well by means of awireline. The tool is lowered through a suitable amount of tubing andthen lifted within the well effecting a seal with the pipe and liftingfluid above the tool to the surface. Packer cups are generally used toseal well pressure in one direction and are mounted on a well tool andpositioned in a sealing engagement with well pipe. Packer cupapplication normally is a static or limited movement application.

There are a multitude of prior well swab bodies using a plurality ofshaped wires held in base structures of various types as the reinforcingstructure. See, for example, U.S. Pat. No. 2,887,347 issued to T. B.Losey. There are also prior well swabs employing metallic cones orcorrugated cylinders as the reinforcing structure. See, for. example,US. Pat. No. 1,898,292 issued to C. S. Crickmer and US. Pat. No.2,013,903 issued to F. A. Thaheld. There are also prior well swabsemploying slotted metallic cylinders as wear protective structures. See,for example, US. Pat. No. 2,619,393 issued to R. E. Wilson and J. A.Wilson and US. Pat. No. 2,456,551 issued to R. A. Wilson.

Difficulty has been experienced in the past with such swab cupreinforcing structures constructed with a cylindrical base havingupstanding tines or fingers pivotally attached to the base. Lack ofcantilevered support from the base allowed the tines to becomemisaligned during the molding process, or required expensive fixturesand time consuming assembly of each finger.

Disadvantages with other unitary cup reinforcing structures made fromtubular material are due to the time consuming machining operations andresultant high cost.

A primary object of this invention is to provide a method and structurefor an improved pressure sealing cup reinforcing structure.

A further object is to provide a method and structure for producing apressure sealing cup reinforcing structure at lower cost.

A further object is to provide an intermediate subassembly reinforcementstructure for a well pressure sealing cup.

SUMMARY OF THE INVENTION These and other objects of the invention aregenerally provided by a well pressure sealing cup reinforcing structurehaving a body with a cylindrical base portion having a noncontinuousperiphery, the body having a plurality of integral, upstanding tines andby the method including the steps of rolling a polyfurcated plate havingan integral base and tines portion rolling the base portion into acylindrical shape and securing the base portion in the cylindricalshape. As an additional feature, an intermediate subassembly is providedfor use in a well pressure sealing cup including a unitary metallicplate with a first edge and an opposite edge and having a continuousportion along the first edge and integral tines extending from thecontinuous por tion to the opposite edge.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation view of anintermediate subas sembly for constructing a well pressure sealing cupreinforcing structure according to this invention.

FIG. 2 is an end elevation view of the subassembly illustrated in FIG.1.

FIG. 3 is a view partially in elevation and partially in cross sectionof a well pressure sealing cup reinforcing structure according to thisinvention.

FIG. 4A is a cross section view of the preferred embodiment taken atsection line 4-4 in FIG. 3.

FIG. 4B is an alternative embodiment of FIG. 4A.

FIG. 4C is still another alternative embodiment of FIG. 4A.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates anintermediate subassembly according to this invention wherein a flatmetallic plate of the general shape illustrated may be used to constructthe reinforcing structure. The length of a first edge 10 is determinedas the approximate circumference for the base of the cup to be morefully described hereinafter. The opposite edge 14 from the first edge 10is the starting point for sheared or sawed slots 16 which begin atopposite edge 14 and proceed to a point 18 near the first edge 10. Withproper tooling known to those skilled in the art, all of the necessarymultiplicity of slits 16 can be sheared or cut with a single stroke of apunch press although many other methods of manufacture are well known tothose with skill in the art.

FIG. 2 illustrates an end view of the semifmished structure in FIG. 1after bends running parallel to the edge 10 have been performed. Bend 20and bend 22 achieve an offset from continuous portion 24 of plate 8 to astraight portion 26 of the tines 28 which were formed by slits 16. Abend 30 positions surface 32 on tine 28 at an angle which provides achamfer or an an gular lead on surface to guide the resulting pressuresealing cup past joints, shoulders and other irregularities in the pipe(not shown) in which the cup will seal.

FIG. 3 illustrates a semi-finished reinforcing structure aftercontinuous portion 24 has been rolled into a generally cylindricalshape. The outside diameter of cylindrical shape of continuous surface24 is illustrated at 24 in FIG. 3. Straight portion 26 of the tines maybe oriented parallel to central axis 34 or at an angle a of 0 to 15.Since the straight portion 26 is on a larger diameter than continuousportion 24, after forming continuous portion 24 into a cylindricalsurface, there will be gaps between the tines since the circumference ata larger diameter 35 is greater than the circumference at diameter 7A.The circumferential length of metal at diameter 35 will be equal to thecircumferential length of metal at diameter 24. However, since thecircumference at diameter 35 is greater than the circumference atdiameter 24, there will be circumferential gaps at diameter 35 since thetine or metallic portion will subtend a smaller angle of are at thelarger diameter than the same width of metal at the diameter at surface241. The slots or gaps between the tines provide for exposure of theelastomer as subsequently molded around the reinforcing structureaccording to this invention whereby the elastomer may feed through theslots between the tines responsive to pressure internal to the cup tomaintain a seal between the cup and the pipe in which it seals while thecup may be performing in a static condition as a packer cup or in adynamic condition as a swab cup. A cylindrical ring 36 may be placed inencircling relationship to cylindrical surface 24! to reinforce thestructure and contain the base to prevent outward movement responsive tointernal pressure in the finished cup. Tines 28 are thus cantileveredfrom continuous portion 24 and are flexible at the free end 38 which wasoriginally the opposite edge M in H0. )1.

American Petroleum institute (AP!) tubing and casing threads representthe largest usage of threaded connections used in oil and gas wells. Thebasic distance is l inch between the ends of two pieces of pipe with APItubing or casing threads threaded into a coupling and tightened with theproper torque. Manufacturing tolerances can allow a particular jointdimension to vary plus or minus 0.5 inches, i.e., between 0.5 and 1.5inches. Since the maximum allowable distance between the end of pipes ina joint is 1.5 inches, the straight portion of a well pressure sealingcup should be at least 1.5 inches so the cup may enter the end of onepiece of pipe before leaving the end of the adjacent piece of pipe. Acup too short to span the gap between pipes could move laterally intothe larger inside diameter of the coupling and allow the cup to becomehung in the gap and could allow the cup to lose sealing engagement withthe pipe.

F [0. 4A illustrates the section 4-4 of FIG. 3. ln F lG. 1, ends 42 and44 of continuous portion 24 are brought together as illustrated in FIG.4A at joint ill. in this embodiment the continuous portion 24 is rolledinto a substantially 360 cylindrical surface to form the reinforcingstructure for a pressure sealing well packer cup or swab cup. The jointill may subsequently be reinforced by the continuous ring 36 or it maybe welded together.

DESCRIPTION OF ALTERNATE EMBODIMENTS FIG. 48 illustrates an alternateembodiment in which a plate with a first edge long enough to formonehalf the circumference of the base of a reinforcing structure isused. Two such base segments may each be formed into a 180 ofcylindrical arc and then assembled with two joints as at 46 and 48 inH6. dB to form a completed reinforcing structure. Joints &6 and 48 maybe reinforced by the addition of a ring 36 or each joint may be welded.

FIG. 4C illustrates another alternative in which each piece ofreinforcing structure forms one-third of the base circumference so thatthree pieces are used to form a completed structure. The three segmentsare then assembled with three joints as at St 52, and 54 and may bereinforced by addition of ring 36. Alternative embodiments asillustrated in FIGS. 48 and 4C may lend themselves more readily tosingle stroke forming in a punch press operation and thereby offereconomies of manufacture.

After considering these examples, skilled persons will understand thatvariations may be made without departing from the principles disclosedand l contemplate the employment of any structures, arrangement, ormodes of manufacture that are properly within the scope of the appendedclaims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

ll. In an intermediate subassembly for use as a reinforcing structure ina well pressure sealing cup of the type having an elastomeric elementbonded on all sides of said reinforcing structure, the improvementcomprising:

a relatively flat, rectangular, unitary metallic plate having a firstedge and an opposite, generally parallel edge, and having a continuousportion along said first edge with integral tines extending from saidcontinuous portion to said opposite edge and with spaced longitudinalgaps between said tines; with said tines and said continuous portionremaining at least partially coplanar.

2. Apparatus according to claim I further comprising said plate having aplurality of bends parallel to said first edge.

3. Apparatus according to claim 2 wherein a substantially straightportion of said tines extends a distance of at least 1.5 inches.

4. Apparatus according to claim 3 wherein said straight portion of saidtines forms an angle from 0 to 15 with said continuous portion of saidplate.

5. Apparatus according to claim 3 with two of said plurality of bendslocated between said straight portion of tines and said first edge.

6. Apparatus according to claim 5 with another of said bends locatedbetween said straight portion and the free ends of said tines.

7. Apparatus according to claim 6 wherein said another bend is locatedfrom the free ends of said tines between 10 and 50 percent of the lengthof said tines.

UNITED STATES PATENT OFFICE" CERTIFICATE OF CORRECTION Patent No. 3Dated June 51! lnventofls) Robert F. Berry & Henry WI Blackwell It iscertified that error appears in the above-identified patent and thatsaidLetters Patent are hereby corrected as shown below:

On the Title page the following should be added:

-- ['75] Assignee: Dresser Industries, Inc,

Signed and sealed this 26th day of Noireiuber 19m (SEAL) Attest:

McCOY M. GIBSQN JR. 0. MARSHALL DANYN Attesting Officer Commissioner ofPatents I USCOMM-DC 603764 69 FORM PO-IOSO (1069) V u,s. covsnuucmrmn'rms omcz; 930

1. In an intermediate subassembly for use as a reinforcing structure ina well pressure sealing cup of the type having an elastomeric elementbonded on all sides of said reinforcing structure, the improvementcomprising: a relatively flat, rectangular, unitary metallic platehaving a first edge and an opposite, generally parallel edge, and havinga continuous portion along said first edge with integral tines extendingfrom said continuous portion to said opposite edge and with spacedlongitudinal gaps between said tines; with said tines and saidcontinuous portion remaining at least partially coplanar.
 2. Apparatusaccording to claim 1 further comprising said plate having a plurality ofbends parallel to said first edge.
 3. Apparatus according to claim 2wherein a substantially straight portion of said tines extends adistance of at least 1.5 inches.
 4. Apparatus according to claim 3wherein said straight portion of said tines forms an angle from 0* to15* with said continuous portion of said plate.
 5. Apparatus accordingto claim 3 with two of said plurality of bends located between saidstraight portion of tines and said first edge.
 6. Apparatus according toclaim 5 with another of said bends located between said straight portionand the free ends of said tines.
 7. Apparatus according to claim 6wherein said another bend is located from the free ends of said tinesbetween 10 and 50 percent of the length of said tines.